Body Structures Determining Differences in Forearm and Upper Arm Blood Pressures

Anatomical Determinants of Forearm and Upper Arm Oscillometric Blood Pressure Differences

The first purpose of this study is to see how blood pressures taken at different sites, specifically the forearm, upper arm and heart vessels, are different. The second purpose is to see if body structures such as vessel size and depth, size of the arm, and amount of tissue in the arm influence differences in blood pressures taken at these sites. The third purpose is to develop a mathematical model of the waves generated by the arm arteries (brachial and radial) to predict differences in forearm and upper arm blood pressures. The results of the study may be used to design more accurate non-invasive blood pressure monitors for the forearm site.

Study Overview

• Status: Completed
• Conditions: Blood Pressure

Detailed Description

Accurate blood pressure (BP) measurement is required to provide appropriate healthcare. Inaccurate BPs may lead to under and/or over-treatment of health conditions and medical diseases such as hypertension. Blood pressure (BP) measurement using automatic, non-invasive oscillometric monitors is common in clinics, physicians'offices and hospital settings. The brachial (upper arm) site is the gold standard for non-invasive BPs. However, in some situations, this site is inaccessible due to injury, surgery, dialysis shunts, intravenous devices, and lymphedema. When the upper arm is difficult to access or the available BP cuffs do not fit an individual's arm, the forearm site is often the preferable alternative. The increased incidence of obesity nationally also contributes to the heightened use of forearm BPs. Questions remain concerning the accuracy of forearm non-invasive BP measurements. Although most researchers report that upper arm and forearm readings are not interchangeable, size of differences vary for individuals and factors influencing differences in readings have not been thoroughly investigated.

• Study Type: Observational
• Enrollment (Actual): 51

Contacts and Locations

Study Locations

• United States
  • Delaware
    • Newark, Delaware, United States, 10718
      • Christiana Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

patients undergoing non-emergent cardiac catheterization

Description

Inclusion Criteria:

• 18 years of age
• able to speak and write in English

Exclusion Criteria:

• Individuals with non-intact skin where the BP cuffs would be placed
• Individuals with injury or surgery to the arm within the last month
• Individuals with lymphedema in the limb selected for measurements
• Individuals with arteriovenous fistulas
• Individuals with differences > 5 mm Hg between right and left arm oscillometric systolic BP measurements
• Individuals with documented valvular disease
• Individuals with atrial fibrillation or atrial flutter (as recommended by BP device manufacturers due to device inaccuracy)
• Individuals with an International Normalized Ratio (INR) > 1.7
• Individuals with intravenous catheters in both arms
• Individuals who require immediate cardiac surgery or unanticipated emergency treatment or who are unstable during the procedure

Study Plan

How is the study designed?

Design Details

• Observational Models: Case-Only
• Time Perspectives: Prospective

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
anatomical determinants of forearm and upper arm blood pressure differences	body mass index, upper arm circumference, biceps skin-fold measurement, forearm and upper arm vessel diameter, forearm and upper arm vessel depth	6 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
blood pressure differences; quantitative model of waveform propagation and reflection able to predict differences between upper arm and forearm blood pressures	blood pressure at forearm, upper arm, aortic root radial artery tonometry to determine radial artery waveform and pressure measurements non-invasively	6 months

Collaborators and Investigators

• Sponsor: Christiana Care Health Services
• Collaborators: University of Delaware
• Investigators: Principal Investigator: Kathleen A Schell, PhD, University of Delaware

Publications and helpful links

General Publications

• Schell K, Lyons D, Bradley E, Bucher L, Seckel M, Wakai S, Carson E, Waterhouse J, Chichester M, Bartell D, Foraker T, Simpson EK. Clinical comparison of automatic, noninvasive measurements of blood pressure in the forearm and upper arm with the patient supine or with the head of the bed raised 45 degrees: a follow-up study. Am J Crit Care. 2006 Mar;15(2):196-205.
• Schell K, Bradley E, Bucher L, Seckel M, Lyons D, Wakai S, Bartell D, Carson E, Chichester M, Foraker T, Simpson K. Clinical comparison of automatic, noninvasive measurements of blood pressure in the forearm and upper arm. Am J Crit Care. 2005 May;14(3):232-41.
• Schell K, Morse K, Waterhouse JK. Forearm and upper-arm oscillometric blood pressure comparison in acutely ill adults. West J Nurs Res. 2010 Apr;32(3):322-40. doi: 10.1177/0193945909351887.
• Schell K, Waterhouse,JK. Comparison of forearm and upper arm automatic noninvasive blood pressures in college students. Internet Journal of Advanced Nursing Practice 2007, 9 (1): 10 pages
• Schell KA, Richards JG, Farquhar WB. The effects of anatomical structures on adult forearm and upper arm noninvasive blood pressures. Blood Press Monit. 2007 Feb;12(1):17-22. doi: 10.1097/MBP.0b013e3280858cd0.
• Rose WC, Johnson DA, Spaeth JR, Edwards J, Beris, AN. Computational and experimental investigation of arterial hemodynamics. Proc. 2008 Int. Mech. Eng. Conf. Exp. Boston: ASME, 2008; 1-8.

Study record dates

Study Major Dates

• Study Start: March 1, 2010
• Primary Completion (Actual): March 1, 2012
• Study Completion (Actual): August 1, 2012

Study Registration Dates

• First Submitted: March 8, 2010
• First Submitted That Met QC Criteria: March 15, 2010
• First Posted (Estimate): March 16, 2010

Study Record Updates

• Last Update Posted (Estimate): November 7, 2012
• Last Update Submitted That Met QC Criteria: November 6, 2012
• Last Verified: November 1, 2012

More Information

Terms related to this study

• Keywords: tonometry; anthropometric measurements; oscillometric blood pressure; cuff site; forearm blood pressure; upper arm blood pressure; site of blood pressure measurement; measurement accuracy
• Other Study ID Numbers: CCC29150; NURS175154 (Other Identifier: University of Delaware IRB)